live-image: real /init + verbose boot for first-boot diagnosis

Host boots past kernel init and then stalls silently. ACPI DSDT error
about TXHC.RHUB.SS01 is benign noise (Tiger Lake firmware bug) — the
actual problem is that nothing between kernel handoff and (maybe)
systemd is visible on the console.

Two changes:

1. Replace the /init → sbin/init symlink with a real shell script
   (live-image/mkosi.extra/init) that mounts /proc /sys /dev /dev/pts
   /dev/shm /run before execing systemd. Systemd has fallback mount
   code for these, but when it fails the failure is silent. Doing it
   explicitly in /init keeps failures visible and avoids the fragile
   symlink-resolution trick.

2. Drop 'quiet' from the kernel cmdline and add loglevel=7 plus
   systemd.log_target=kmsg + journald.forward_to_console=1 so every
   early-boot message reaches both tty0 and ttyS0. Will be dialed
   back once boot is stable.

Also: .gitattributes pins LF on live-image/, .gitea/, Makefile, and
*.sh so Windows checkouts don't break shell scripts and Makefile
recipes with CRLF. /init also gets chmod 0755 in repack-initrd as a
belt-and-braces against mode loss on non-Linux checkouts.

live-image/Makefile

@@ -32,9 +32,11 @@ repack-initrd:
 	@# copies (release tarball) don't have to follow links.
 	@cp -fL build/vmlinuz build/vmlinuz.real && mv build/vmlinuz.real build/vmlinuz
 	@rm -f build/initrd.img build/initrd.img.old build/vmlinuz.old
-	@# Kernel execs /init from the unpacked initramfs. systemd-sysv puts
-	@# init at /sbin/init; add the top-level symlink the kernel looks for.
-	@[ -e build/init ] || ln -sf sbin/init build/init
+	@# /init ships via mkosi.extra/init as a shell script that sets up
+	@# api-vfs mounts and execs systemd. Force the exec bit on here —
+	@# Windows checkouts don't preserve +x, and mkosi.extra copies the
+	@# source-tree mode straight through.
+	@chmod 0755 build/init
 	@# Skip /boot: holds the old kernel + stub initrd, both superseded.
 	@# Write to a sibling temp path so find doesn't race with the
 	@# archive being written into the dir it's walking.

live-image/mkosi.extra/init

@@ -0,0 +1,31 @@
+#!/bin/sh
+# /init — PID 1 entry point for the everything-in-initramfs live image.
+#
+# The kernel unpacks our cpio.zst into a ramfs, sees no root= parameter,
+# and execs /init. Classic initramfs-tools has an elaborate /init that
+# mounts a real rootfs and pivot_roots into it; we don't do that —
+# there IS no other rootfs, the initramfs IS the rootfs. All we need
+# to do is set up the api-vfs mounts systemd expects before PID 1 and
+# hand off.
+#
+# Running systemd directly as PID 1 from kernel /init works (systemd
+# detects it's PID 1 and boots normally), but only if /proc, /sys, /dev
+# are pre-mounted. Systemd has fallback mount code for these, but it's
+# fragile in the ramfs-rootfs case — doing it here explicitly makes
+# first-boot failures easier to see and harder to hit.
+
+set -e
+
+echo "vetting-init: bootstrapping api-vfs"
+
+mount -t proc     -o nosuid,noexec,nodev        proc     /proc
+mount -t sysfs    -o nosuid,noexec,nodev        sysfs    /sys
+mount -t devtmpfs -o mode=0755,nosuid           devtmpfs /dev
+mkdir -p /dev/pts /dev/shm /run
+mount -t devpts   -o gid=5,mode=620,nosuid,noexec devpts /dev/pts
+mount -t tmpfs    -o mode=1777,nosuid,nodev     tmpfs    /dev/shm
+mount -t tmpfs    -o mode=0755,nosuid,nodev     tmpfs    /run
+
+echo "vetting-init: handing off to systemd"
+
+exec /lib/systemd/systemd